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United States Patent |
5,554,030
|
Ario
,   et al.
|
September 10, 1996
|
Method for bonding non-amalgam restorative materials to dental surfaces
Abstract
A method for adhering non-amalgam dental restorative materials to a dental
surface comprising the steps of a) etching the dental surface with acid,
b) applying a treatment composition comprising an electron donor to the
etched dental surface, c) applying a priming solution containing a
film-former to the treated dental surface, d) applying a chemically
curable dental adhesive to the primed dental surface, and e) applying
non-amalgam dental restorative material to the adhesive-coated dental
surface. The treatment composition comprises an electron donor compound
selected such that the dental restorative has a higher Adhesive Shear Bond
Strength than a like method without said electron donor compound.
Inventors:
|
Ario; Paula D. (Minneapolis, MN);
Aasen; Steven M. (Woodbury, MN)
|
Assignee:
|
Minnesota Mining and Manufacturing Company (St. Paul, MN)
|
Appl. No.:
|
268773 |
Filed:
|
June 30, 1994 |
Current U.S. Class: |
433/226; 433/228.1 |
Intern'l Class: |
A61C 005/04; A61C 005/00 |
Field of Search: |
433/218,219,226,228.1
|
References Cited
U.S. Patent Documents
3513123 | May., 1970 | Saffir.
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3574943 | Apr., 1971 | Stark et al.
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3882600 | May., 1975 | Plymale.
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4001483 | Jan., 1977 | Lee, Jr. et al. | 526/270.
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4064629 | Dec., 1977 | Stoner et al.
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4182035 | Jan., 1980 | Yamauchi et al. | 433/228.
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4235633 | Nov., 1980 | Tomioka et al. | 106/35.
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4251565 | Feb., 1981 | Bowen | 433/226.
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4259117 | Mar., 1981 | Yamauchi et al. | 106/35.
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4368043 | Jan., 1983 | Yamauchi et al. | 433/217.
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4383052 | May., 1983 | Higo.
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4499251 | Feb., 1985 | Omura et al. | 526/278.
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4515930 | May., 1985 | Omura et al. | 526/276.
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4535102 | Aug., 1985 | Kusumoto et al. | 523/116.
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4537940 | Aug., 1985 | Omura et al. | 526/278.
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4539382 | Sep., 1985 | Omura et al. | 526/276.
|
4540722 | Sep., 1985 | Bunker | 523/109.
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4544467 | Oct., 1985 | Bunker et al. | 204/159.
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4669983 | Jun., 1987 | Bunker | 433/217.
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4719149 | Jan., 1988 | Aasen et al. | 433/226.
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4830616 | May., 1989 | Okuda | 433/217.
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4872936 | Oct., 1989 | Engelbrecht | 156/307.
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4880660 | Nov., 1989 | Aasen et al. | 433/226.
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4929746 | May., 1990 | Bunker | 558/92.
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5141436 | Aug., 1992 | Orlowski et al. | 433/226.
|
5256447 | Oct., 1993 | Oxman et al. | 427/207.
|
5264513 | Nov., 1993 | Ikemura et al. | 526/318.
|
5276068 | Jan., 1994 | Waknine | 522/28.
|
Foreign Patent Documents |
0058483 | Aug., 1982 | EP.
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0237233 | Sep., 1987 | EP.
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0234934 | Sep., 1987 | EP.
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0348718 | Jan., 1990 | EP.
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0408357 | Jan., 1991 | EP.
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0423430 | Apr., 1991 | EP.
| |
0609902 | Oct., 1994 | EP.
| |
0661034 | May., 1995 | EP.
| |
2561521 | Sep., 1985 | FR.
| |
2739282 | Feb., 1978 | DE.
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57-143372 | Sep., 1982 | JP.
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57-167364 | Oct., 1982 | JP.
| |
63-175085 | Jul., 1988 | JP.
| |
63-250310 | Oct., 1988 | JP.
| |
2261223 | Dec., 1993 | GB.
| |
WO93/12790 | Aug., 1993 | WO.
| |
Other References
Abstract; Derwent Publications Ltd., London, Mitsui Petrochem Ind KK Jul.
2, 1985.
International Search Report.
M. Staninec and M. Holt, Journal of Prosthetic Dentistry (1988), vol. 59,
pp. 397-402.
A. Lacey and M. Staninec, Quintessence International (1989), vol. 20, pp.
521-524.
Y. Torii et al. Operative Dentistry (1989), vol. 14, pp. 142-148.
CRA Newsletter; Adhesives, Silver Amalgam, (Feb. 1994).
Y. Aboush and C. Jenkins, Br. Dent. J. (1989), vol. 166, pp. 255-257.
Y. Aboush and R. Elderton, Br. Dent. J. (1991), vol. 170, pp. 219-222.
Y. Aboush and R. Elderton, Dent. Mater. (1991), vol. 7, pp. 130-132.
A. Ben-Amar, J. Am. Dent. Assoc. (1989), vol. 119, pp. 725-728.
M. Mitrosky, Jr., Quintessence International (1981), vol. 9, pp. 871-874.
H. J. Staehle et al., Dtsch. Zahnartzt (1988), vol. 43, pp. 952-957.
M. Buonocore, W. Wileman, and F. Brudevold, J. Dent. Res., 35, 846 (1956).
M. Buonocore and M. Quigley, J. Amer. Dent. Assoc., 57, 807 (1958).
M. Anbar and E. Farley, J. Dent. Res., 53, 879 (1974).
E. Farley, R. Jones, and M. Anbar, J. Dent. Res., 56, 943 (1977).
|
Primary Examiner: Lucchesi; Nicholas D.
Attorney, Agent or Firm: Griswold; Gary L., Kirn; Walter N., Bjorkman; Dale A.
Claims
What is claimed:
1. A method for adhering a non-amalgam dental restorative to a dental
surface comprising, in order, the steps of
a) etching said dental surface with acid,
b) applying a treatment composition comprising an electron donor compound
to said etched dental surface, thereby providing a treated dental surface,
c) applying a priming solution containing a film-former to said treated
dental surface, thereby providing a primed dental surface,
d) applying a chemically curable dental adhesive to said primed dental
surface thereby providing an adhesive-coated dental surface, and
e) applying a non-amalgam dental restorative to said adhesive-coated dental
surface; wherein said electron donor compound is selected such that the
dental restorative has a higher Adhesive Shear Bond Strength than a like
method without said electron donor compound.
2. The method of claim 1, wherein said dental surface is hard tissue.
3. The method of claim 2, wherein said hard tissue is dentin.
4. The method of claim 2, wherein said hard tissue is enamel.
5. The method of claim 1, wherein said dental surface is porcelain.
6. The method of claim 1, wherein said dental surface is previously placed
amalgam.
7. The method of claim 1, wherein said dental surface is metal.
8. The method of claim 1, wherein said treatment composition comprises
sodium benzenesulfinate.
9. The method of claim 8, wherein said treatment composition comprises
water.
10. The method of claim 1, wherein said priming solution comprises an acid
having a pKa of less than about 10.
11. The method of claim 1, wherein said priming solution comprises HEMA.
12. The method of claim 1, wherein said priming solution comprises
polyalkenoic acid copolymer.
13. The method of claim 1, wherein said chemically curable dental adhesive
comprises a redox polymerization initiator system.
14. The method of claim 1, wherein said restorative is a dental composite
restorative.
15. The method of claim 1, wherein said adhered dental restorative exhibits
a Shear Adhesive Strength to dentin greater than about 30 kg/cm.sup.2.
16. The method of claim 1, wherein said adhered dental restorative exhibits
a Shear Adhesive Strength to dentin greater than about 60 kg/cm.sup.2.
Description
FIELD OF THE INVENTION
The present invention relates to bonding of non-amalgam restorative
materials to dental surfaces. More specifically, the present invention
relates to multiple-step procedures for bonding non-amalgam dental
restorative materials to hard tissue, set amalgam or other surfaces of the
oral environment.
BACKGROUND OF THE INVENTION
U.S. Patent No. 5,276,068 to Waknine discloses dental compositions useful
for bonding dental surfaces, including enamel, dentin, porcelain and
metallic surfaces, comprising polycarbonate dimethacrylate condensation
products as a principle component, and a secondary monomer such as BIS-GMA
or polyurethane dimethacrylate or the like as a second component, which is
provided to impart strength to the dental composition. Also described
therein are methods for bonding dental restorative materials to an exposed
dentin surface, wherein the surface can be pretreated by application of 3%
H.sub.2 O.sub.2, 17% EDTA, or 5% NaOCl in non-vital teeth followed by an
alcohol or acetone solution of an alkali metal salt of benzenesulfinic
acid with subsequent evaporation of the alcohol from the solution.
Alternatively, the surface can be pretreated by first applying an alcohol
or acetone solution of an alkali metal salt of benzenesulfinic acid and
then applying an acetone solution of N-phenylglycine. The treated dentin
surface is then coated with a resinous adhesive. The adhesive is then
cured and an appropriate dental restorative material is applied.
SUMMARY OF THE INVENTION
The present invention provides a method for adhering non-amalgam dental
restorative materials to a dental surface comprising the steps of a)
etching the dental surface with acid, b) applying a treatment composition
comprising an electron donor to the etched dental surface, c) applying a
priming solution containing a film-former to the treated dental surface,
d) applying a chemically curable dental adhesive to the primed dental
surface, and e) applying non-amalgam dental restorative material to the
adhesive-coated dental surface, wherein the treatment composition
comprises an electron donor compound selected such that the dental
restorative has a higher Adhesive Shear Bond Strength than a like method
without said electron donor compound.
DETAILED DESCRIPTION
The present invention offers distinct advantages to the dental patient for
receiving comparatively low cost and low trauma dental care. With the
present method of bonding non-amalgam restorative materials to various
dental surfaces, the dentist can perform repairs using a low cost material
with which he or she is familar. These repairs can now be made with
substantially less preparation than required previously.
Additionally, the present method allows bonding of non-amalgam dental
restorative materials to dental surfaces other than tooth structure that
previously could not be repaired using these materials without complete
removal of prior dental work. The present method bonds non-amalgam dental
restorative materials to previously placed amalgam, metal (such as in
pins, posts, and bridgework), glass ionomers, porcelain, previously placed
composite restorations, or other materials used in the oral environment.
Generally, before the present method is carried out, the area of the oral
cavity to be worked on is prepared using conventional dental techniques.
For example, hard tissue (e.g. enamel or dentin) to which the non-amalgam
dental restorative material is to be applied preferably is first cleaned
using conventional methods (e.g., by abrading it with a bur), rinsed
(e.g., using water) and dried (e.g., using air).
In the first step of the present method, the dental surface is etched with
acid. An appropriate acid etch technique may be used to provide a surface
receptive to bonding materials thereto.
Acids for use in the acid etch step can be inorganic or organic acids, and
if organic can be monomeric, oligomeric or polymeric. If desired, a
precursor to the acid such as an acid anhydride, e.g., 4-Methacryloxyethyl
Trimellitate Anhydride (4-META), acid halide (including inorganic acid
halides such as Lewis acids, e.g., ferric chloride, and organic acid
halides), or ester can be used in place of the acid itself, e.g., to
generate the desired acid in situ. Suitable acids include mineral acids,
carboxylic acids, sulfonic acids, and phenols, with carboxylic acids,
alkylsulfonic acids, arylsulfonic acids, and phosphonic acids being
preferred.
The acid has a pKa in water that is less than or equal to that of phenol.
Preferably, the pKa of the acid is between about -20 and about +10, more
preferably between about -10 and about +5.
Suitable inorganic acids include HBr, HCl, and HNO.sub.3. Suitable organic
acids include acetic acid, .alpha.-chloropropionic acid,
2-acrylamido-2-methylpropane sulfonic acid, acrylic acid, benzenesulfonic
acid, benzoic acid, bromoacetic acid, 10-camphorquinone-sulfonic acid,
10-camphorsulfonic acid, chloroacetic acid, citraconic acid, citric acid,
dibromoacetic acid, dichloroacetic acid, di-HEMA ester of 1,2,4,5
benzenetetracarboxylic acid, 2,4-dinitrophenol, formic acid, fumaric acid,
2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, maleic acid, methacrylic
acid, 2-naphthalene sulfonic acid, nitric acid, oxalic acid,
p-nitrophenol, phenol, phosphoric acid, phosphorous acid esters (such as
2,2'-bis(.alpha.-methacryloxy-.beta.-hydroxypropoxyphenyl) propane
diphosphonate (Bis-GMA diphosphonate), dibutyl phosphite, di-2-ethylhexyl
phosphate, di-2ethylhexyl phosphite, hydroxyethyl methacrylate
monophosphate, glyceryl dimethacrylate phosphate, glyceryl-2-phosphate,
glycerylphosphoric acid, methacryloxyethyl phosphate, pentaerythritol
triacrylate monophosphate, pentaerythritol trimethacrylate monophosphate,
dipentaerythritol pentaacrylate monophosphate, and dipentaerythritol
pentamethacrylate monophosphate), pivalic acid, propionic acid, sulfuric
acid, toluene sulfonic acid, tribromoacetic acid, trichloroacetic acid,
trifluoroacetic acid, trifluoromethanesulfonic acid, and trihydroxybenzoic
acid. Mixtures of such acids can be used if desired.
Where the dental surface to be bonded to is dentin, preferably the acid
does not generate insoluble salts of calcium during the etch technique in
an amount that would detrimentally affect adhesion to the oral surface. If
the acid does generate insoluble calcium salts, the salts are preferably
rinsed from the dental surface before subsequent steps are taken.
Under typical conditions, the dental surface to be bonded is first exposed
to about 0.01-0.2 ml of acid solution for a period of about 5-60 seconds.
Preferred etching solutions contain about 10% maleic acid or about 35%
phosphoric acid. Generally, the higher the acid strength and
concentration, the shorter the time of exposure to the acid solution
required to achieve the desired effect. This acid may be applied with
dropper sponge or brush. The acid solution may optionally be dried on the
dental surface by, e.g. air. Preferably, no drying step is taken after
acid etch.
After the dental surface is etched with acid, a treatment composition
comprising an electron donor is applied to the etched dental surface. The
donor has an E.sub.ox greater than zero and less than or equal to E.sub.ox
(p-dimethoxybenzene). Preferably E.sub.ox (donor) is between about 0.5 and
1 volts vs. a saturated calomel electrode ("S.C.E."). E.sub.ox (donor)
values can be measured experimentally, or obtained from references such as
N. L. Weinburg, Ed., Technique of Electroorganic Synthesis Part II
Techniques of Chemistry, Vol. V (1975), and C. K. Mann and K. K. Barnes,
Electrochemical Reactions in Nonaqueous Systems (1970).
Preferred donors include ascorbic acid, metal complexed ascorbic acid,
cobalt (II) chloride, ferrous chloride, ferrous sulfate, hydrazine,
hydroxylamine, oxalic acid, thiourea, tertiary amines (such as
N,N-bis-(2-hydroxyethyl)-p-toluidine, 4-(dimethylamino)-phenethyl alcohol
and the like), and aromatic salts of a dithionite, thiosulfate, or sulfite
anion.
A preferred electron donor is the aromatic sulfinate salt represented by
the general formula
##STR1##
wherein
R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 may be any atoms and/or
groups as long as they are inert to the double bond of monomers. Examples
are hydrogen, fluoro, chloro, bromo, iodo, methyl, ethyl, 2-chloroethyl,
2-bromo-2-chloroethyl, propyl, isopropyl, per-fluoropropyl, allyl, butyl,
isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl,
tert-pentyl, cyclohexyl, phenyl and 4-bromophenyl.
M.sup.n+ is a cation with mono-valency to 4-valency that can, as a counter
ion for sulfinic acid anion, form the sulfinate. Examples of M.sup.n+ are
alkali metal ions, such as Li.sup.+, Na.sup.+, K.sup.+, and Cs.sup.+,
alkaline earth metal ions, such as Be.sup.2+, Mg.sup.2+, Ca.sup.2+,
Sr.sup.2+ and Ba.sup.2+, transition metal ions such as Cr.sup.2+,
Cr.sup.3+, Mn.sup.2+, Fe.sup.2+, Fe.sup.3+, Co.sup.2+, Co.sup.3+,
Ni.sup.2+, Cu.sup.2+, Zn.sup.2+, Rh.sup.3+, Pd.sup.2+, Ag.sup.+,
Cd.sup.2+, Ir.sup.3+, Ir.sup.4+, and Hg.sup.2+, and ammonium ions, such as
NH.sub.4.sup.+, (CH.sub.3 CH.sub.2).sub.3 NH.sup.+,
##STR2##
Preferred counter ions among these ions are Li.sup.+, Na.sup.+, K.sup.+,
Mg.sup.2+, and Ca.sup.2+, since sulfinates thereof have good stability
when stored in monomers and have good solubility in the monomers.
Particularly preferred aromatic sulfinate salts include sodium
benzenesulfinate and sodium toluenesulfinate. Optionally, the treatment
composition may comprise mixtures of more than one aromatic sulfinate
salt.
The electron donor is preferably provided in an appropriate solvent, such
as water, acetone, lower alkyl alcohols (such as methanol, ethanol,
propanol), and the like.
Optionally the treatment composition containing the electron donor may
comprise other adjuvants, such as polymerization catalysts, medicaments,
fluoride compounds, indicators, dyes, wetting agents, buffering agents,
thixotropes and the like.
The treatment composition preferably comprises at least 0.1% by weight of
electron donor, more preferably between 0.5 and 15, and most preferably
between one and 10%. The treatment composition may be applied by any
appropriate means, such as by dropper, sponge or brush. This composition
is preferably allowed to reside on the etched surface for about 1-60
seconds.
The treatment composition is optionally dried on the surface with air, or
the solvent is allowed to evaporate. After the treatment composition
comprising an electron donor is applied to the etched dental surface, a
priming solution containing a film-former is applied to the treated dental
surface. For purposes of the present invention, a film-former is defined
as a composition capable of forming a hardenable (e.g., polymerizable)
continuous or semicontinuous film on the dental surface.
The film-former used in the primer of the present invention is preferably a
water-dispersible substance or water-dispersible mixture of substances,
such substance(s) being organic monomers, oligomers, polymers, or
cosolvents. Most preferably, the film former contains at least one polymer
prior to application to the treated dental surface. As used herein, a
"water-dispersible" film former has a water dispersibility or more
preferably a water solubility (exclusive of any water that may be present
in the film former) of at least about 5 weight percent. Most preferably,
the film former can be mixed with water in all proportions. For brevity,
dispersible and soluble will sometimes be referred to collectively as
dispersible. As used herein, "solubility" means the capability of a
substance to form a solution, i.e., either a true solution or a colloidal
solution. A true solution being a uniformly dispersed mixture at the
molecular or ionic level, of one or more substances (the solute) in one or
more substances (the solvent). These two parts of a solution are called
phases. A colloidal dispersion is often called a solution. Since colloidal
particles are larger than molecules it is strictly incorrect to call such
dispersions solutions; however this term is widely used in the literature.
As used herein, "dispersibility" means the capability of a substance to
form a dispersion, i.e., a two-phase system where one phase consists of
finely divided particles (often in the colloidal size range) distributed
throughout a bulk substance, the particles being the disperse or internal
phase and the bulk substance the continuous or external phase.
Preferred film formers contain one or more substances having a sufficient
number of water-dispersing groups such as hydroxyl groups, carboxyl
groups, sulfonic acid groups, cationic salts (e.g., ammonium, phosphonium
or sulfonium groups), amide linkages or polyether linkages to render the
film former water-dispersible. The film former, prior to removal of any
volatile components, preferably wets the dental surface and most
preferably has a sufficiently low viscosity to enable it to flow into
interstices that already exist in the dental surface or that are created
therein by the action of the acid. After removal of any volatile
components, the film former preferably has a sufficiently high viscosity
to enable it to resist displacement by dentinal fluids (in the case where
the dental surface is dentin) or other extraneous liquids. The film former
preferably contains one or more polymerizable substances. Addition
polymerizable substances (e.g., vinyl compounds such as acrylates and
methacrylates) are especially preferred.
Suitable preferred polymer components in the film former include linear,
branched or cyclic polymers formed prior to priming of the treated dental
surface. For purposes of this invention, a polymer is a chemical compound
having at least two repeat units. They can be polymers of ethylenically
unsaturated monomers or they can be polymeric compounds like polyester,
polyamide, polyether, polyethyleneglycol, polyethyleneglycol
dimethacrylate and diacrylate, polysaccharide, cellulosic, polypropylene,
polyacrylonitrile, polyurethane, poly(vinyl chloride), poly(methyl
methacrylate), phenol-formaldehyde, melamine-formaldehyde, and
urea-formaldehyde. Mixtures of such polymers can be used if desired.
Preferred polymers are the polymers of ethylenically unsaturated monomers.
These polymers may be homo- or co-polymers and may contain hydrophilic or
hydrophobic groups. The polymer may optionally contain acid groups, their
salts, or their reactive derivative groups. Particularly preferred
polymers contain reactive groups that further react (i.e., crosslink or
copolymerize) with the other components of the film former or the dental
adhesive. Addition polymerizable reactive groups (e.g., vinyl groups such
as acrylates and methacrylates) are especially preferred. Polymers of
ethylenically unsaturated monomers are often used in dental glass ionomer
cements. These polymers are especially useful in the present invention as
they generally have good biocompatibility, are dispersible in water and
have a suitable molecular weight. Particularly preferred polymers contain
functional groups that have an affinity for hard tissue. For example, such
groups include .beta.-dicarbonyl groups and carboxylic acid groups. The
polymer component of an ionomer cement is often a copolymer of acrylic
acid and itaconic acid, although other monomers may be incorporated, and
are herein referred to as polyalkenoic acids. See generally, Prosser et
al., Developments in Ionic Polymers- 1, Chapter 5, Applied Science
Publishers (London and New York, 1983). Recently such polymers have been
further modified in the laboratory of the assignee of this invention by
the incorporation of addition polymerizable reactive groups as mentioned
above. Their preparation is described in U.S. Pat. No. 5,130,347.
Preferred polymeric compounds used in the primer of the invention have a
weight average molecular weight prior to hardening of more than about 500,
although preferably no greater than 2,000,000. More preferably, polymeric
compounds for use in the primer have a weight average molecular weight
prior to hardening of between about 1,000 and 1,000,000 evaluated against
a polystyrene standard using gel permeation chromatography. Most
preferably, polymeric compounds for use in the primer have a weight
average molecular weight prior to hardening of between about 5,000 and
200,000.
Suitable monomer components in the film former include
2-hydroxyethylacrylate, 2-hydroxyethylmethacrylate ("HEMA"), 2- and
3-hydroxypropylacrylate and methacrylate, 1,3- and
2,3-dihydroxypropylacrylate and methacrylate,
2-hydroxypropyl-1,3-diacrylate and dimethacrylate,
3-hydroxypropyl-1,2-diacrylate and dimethylacrylate, pentaerythritol
diacrylate and dimethacrylate, acrylic acid, methacrylic acid,
2-trimethylammonium ethylmethacrylic chloride,
2-acrylamido-2-methylpropane-sulfonic acid, acrylamide, methacrylamide,
2-hydroxyethylacrylamide and methacrylamide,
N,N-bis(2-hydroxyethyl)acrylamide and methacrylamide,
N-alkyl-N-hydroxyethyl acrylamides and methacrylamides, 2- and
3-hydroxypropylacrylamide and methacrylamide,
methacrylamidopropyltrimethylammonium chloride, polyethyleneglycol (400)
diacrylate and dimethacrylate, glycerol dimethacrylate and diacrylate,
gylcerol monomethacrylate and monoacrylate, pentaerylthritol
trimethacrylate and triacrylate, and mixtures thereof. It is expected that
where an acrylate monomer is suitable the methacrylate analog will
likewise be suitable.
Alternatively, water insoluble or sparingly water soluble components may
also be incorporated in useful primers of the present invention. For
example tetraethylene glycol dimethacrylate ("TEGDMA"), a sparingly water
soluble monomer, may provide excellent priming action. Additionally, some
amount of water insoluble components, such as the dimethacrylate derived
from the reaction between methacrylic acid and the diglycidyl ether of
bisphenol A ("Bis-GMA") may also be incorporated in the present primers
with good overall bonding results.
The film former preferably comprises one or more suitable cosolvents. The
cosolvent(s) aid in wetting the dental surface (especially when the
surface is hard tissue) and in solubilizing or dispersing the substances.
Suitable cosolvents include water, alcohols such as methanol, ethanol,
1-propanol, 2-propanol, and 2-methyl-2-propanol, ketones such as acetone
and methylethylketone, aldehydes such as formaldehyde, acetaldehyde,
propionaldehyde, acrolein, glutaraldehyde and 2-hydroxy-adipaldehyde,
amides such as acetamide and N,N-dimethylformamide, and other substances
such as tetrahydrofuran and dimethyl sulfoxide. The film former preferably
contains less than about 95 weight percent cosolvent, more preferably
between about 15 and about 85 weight percent cosolvent.
The primer preferably also is acidic. Acidity may be provided by
incorporating an acid or acid precursor in the priming solution, or by
providing the film-former with acidic functionality. Preferably, the
priming solution has a pH of less than 7.
When the acidity of the primer is provided through incorporation of a
separate acid, the acid may preferably be selected from the same acids
recited above for use in the acid etch step.
The above discussion on selection of film-former components identifies a
number of materials that contain acidic functionality. It will be
appreciated by the skilled artisan that selection of these acid functional
film-formers is preferred for imparting acidity to the primer solution.
The priming solution may optionally contain other adjuvants such as
polymerization catalysts, medicaments, fluoride compounds, indicators,
dyes, wetting agents, buffering agents, thixotropes and the like.
The priming solution is applied by appropriate means, such as a dropper,
sponge or brush, and should be allowed to stand on the dental surface long
enough to provide the desired degree of priming. The standing time will
depend upon the film-former employed, the type of dental surface and the
time available for carrying out the priming procedure. For priming dentin
and enamel, standing times less than about 5 minutes, and preferably about
5 seconds to one minute provide very effective priming, although shorter
or longer times can be used if desired.
The priming solution is optionally hardened on the dental surface before
subsequent steps are taken. Hardening may be achieved by allowing the
priming solution to dry, or optionally polymerizing the film-former. In
order to initiate the polymerization reaction, the film-former may
comprise polymerization catalysts such as those mentioned in columns 28
and 29 of U.S. Pat. No. 4,539,382 and described in more detail below.
Alternatively, the priming solution may contain one or more suitable
photopolymerization initiators that act as a source of free radicals when
activated. Such initiators can be used alone or in combination with one or
more accelerators and/or sensitizers.
The photoinitator should be capable of promoting free radical crosslinking
of the ethylenically unsaturated moiety on exposure to light of a suitable
wavelength and intensity. Visible light photoinitiators are preferred. The
photoinitiator frequently can be used alone, but typically it is used in
combination with a suitable donor compound or a suitable accelerator (for
example, amines, peroxides, phosphorus compounds, ketones and
alpha-diketone compounds).
Preferred visible light-induced initiators include camphorquinone (which
typically is combined with a suitable hydrogen donor such as an amine),
diaryliodonium simple or metal complex salts, chromophore-substituted
halomethyl-s-triazines and halomethyl oxadiazoles. Particularly preferred
visible light-induced photoinitiators include combinations of an
alpha-diketone, e.g., camphorquinone, and a diaryliodonium salt, e.g.,
diphenyliodonium chloride, bromide, iodide or hexafluorophosphate, with or
without additional hydrogen donors (such as sodium benzenesulfinate,
amines and amine alcohols).
Preferred ultraviolet light-induced polymerization initiators include
ketones such as benzyl and benzoin, and acyloins and acyloin ethers.
Preferred commercially available ultraviolet light-induced polymerization
initiators include 2,2-dimethoxy-2-phenylacetophenone ("IRGACURE 651 ")
and benzoin methyl ether (2-methoxy-2-phenylacetophenone), both from
Ciba-Geigy Corp.
The photoinitiator should be present in an amount sufficient to provide the
desired rate of photopolymerization. This amount will be dependent in part
on the light source, the thickness of the layer to be exposed to radiant
energy, and the extinction coefficient of the photoinitiator. Typically,
the photoinitiator components will be present at a total weight of about
0.01 to about 5%, more preferably from about 0.1 to about 5%, based on the
total weight of the composition.
After the priming solution is applied to the treated dental surface, a
chemically curable dental adhesive is applied to the primed dental
surface.
The chemically curable dental adhesive comprises polymerizable components
in a formulation that, upon application to the surface to be bonded,
initiates a cure reaction that will result in polymerization of the
adhesive and bonding of restoratives to the dental surface. This cure
reaction takes place without the need to expose the chemically curable
dental adhesive to actinic light. Optionally, however, the dental adhesive
may additionally contain photoinitiators as described above to assist in
curing the adhesive at exposed margins of the amalgam placement.
Generally, chemically curable dental adhesives are provided in a two part
format wherein one part contains one part of a reactive pair, and the
other part the other half of the pair. Optionally, the chemically curable
dental adhesive may be provided in a one part formulation or three or more
part formulation. Upon mixing, these components react, initiating a
polymerization reaction.
A preferred mode for initiation of the polymerization reaction of an
ethylenically unsaturated moiety is the incorporation of an oxidizing
agent and a reducing agent as a redox catalyst system to enable the dental
adhesive to cure via a redox reaction. Various redox systems are described
in U.S. Pat. No. 5,154,762, the disclosure of which is expressly
incorporated herein by reference.
The oxidizing agent should react with or otherwise cooperate with the
reducing agent to produce free radicals capable of initiating
polymerization of the ethylenically unsaturated moiety. The oxidizing
agent and the reducing agent preferably are sufficiently shelf stable to
permit their storage and use under typical dental conditions. The
oxidizing agent and the reducing agent should also be present in an amount
sufficient to permit an adequate free radical reaction rate. This can be
evaluated by combining the ethylenically unsaturated moiety, the oxidizing
agent and the reducing agent and observing whether or not a hardened mass
is obtained.
Suitable oxidizing agents include persulfates such as sodium, potassium,
ammonium and alkyl ammonium persulfates, benzoyl peroxide, hydroperoxides
such as cumene hydroperoxide, tert-butyl hydroperoxide, tert-amyl
hydroperoxide and 2,5-dihydroperoxy-2,5-dimethylhexane, salts of cobalt
(III) and iron (III), hydroxylamine, perboric acid and its salts, salts of
a permanganate anion, and combinations thereof. Hydrogen peroxide can also
be used, although it may, in some instances, interfere with the
photoinitiator, if one is present. The oxidizing agent may optionally be
provided in an encapsulated form as described in U.S. Pat. No. 5,154,762.
Preferred reducing agents include ascorbic acid, metal complexed ascorbic
acid, cobalt (II) chloride, ferrous chloride, ferrous sulfate, hydrazine,
hydroxylamine, oxalic acid, thiourea, tertiary aromatic amines (such as
N,N-bis-(2-hydroxyethyl)-p-toluidine, 4-(dimethylamino)-phenethyl alcohol
and the like), and aromatic salts of a dithionite, thiosulfate,
benzenesulfinate, or sulfite anion.
A preferred dental adhesive is obtained by combining (1) Bis-GMA with (2) a
hydrophilic monomer such as HEMA, hydroxypropyl methacrylate, or
methacrylic acid. Suitable monomers for use in the dental adhesive include
the monomers described above as well as tetrahydrofurfuryl methacrylate,
glyceryl-1,3-dimethacrylate, triethyleneglycol dimethacrylate, ethyl
methacrylate, n-hexyl methacrylate, polyethyleneglycol dimethacrylate
("PEGDMA"), and 1,6-hexanediol dimethacrylate. Optionally, the dental
adhesive may contain polymers of the type described in the discussion of
the priming solution above. The dental adhesive can also contain
cosolvents of the type described above. Preferably the dental adhesive is
copolymerizable with the residual film formed by the primer. If desired,
the dental adhesive can contain conventional fillers, and can also contain
adjuvants of the type described above.
Other preferred dental adhesives which can be employed with the present
invention contain acrylate- or methacrylate-functional polymers and may
also contain phosphorous compounds. In such dental adhesives either a
single phosphorus compound or a mixture of phosphorus compounds can be
used.
If desired, other free-radically polymerizable non-phosphorus-containing
compounds can be mixed with the dental adhesive, for example, as a diluent
to reduce viscosity or promote wetting. Other suitable free-radically
polymerizable compounds include mono- or poly- (e.g., di-, tri- or
tetra-functional) acrylates and methacrylates such as methyl acrylate,
2-hydroxyethyl acrylate, triethyleneglycol diacrylate, neopentylglycol
diacrylate, hexamethyleneglycol diacrylate, trimethylolpropane
triacrylate, pentaerythritol tetraacrylate, polyalkylene glycol mono- and
di-acrylates, urethane mono- or poly-functional acrylates, Bisphenol A
diacrylates, and the corresponding methacrylates of the above compounds,
as well as acrylamides and methacrylamides, vinyl compounds, styrene
compounds, and other olefinically unsaturated compounds suitable for use
in the oral environment. U.S. Pat. Nos. 4,499,251, 4,515,930, 4,537,940
and 4,539,382 contain an extensive list of such compounds.
In use, an adhesive is applied to the primed dental surface after
initiation of the polymerization reaction in an amount effective to bond
the restorative to the dental surface. After the chemically curable dental
adhesive is applied to the primed dental surface, the dental restorative
is applied to the adhesive-coated dental surface. The restorative is
prepared in the conventional manner for placement and applied to the
adhesive coated surface before the dental adhesive is fully cured.
Typically the dental practitioner has sufficient working time after
application of a redox curable dental adhesive in which to place the
restorative before full curing of the adhesive. This working time varies
depending on the redox curable dental adhesive used.
Shear Adhesive Strength Test Method
Adhesion to dentin or enamel was evaluated as follows:
First, teeth (five bovine teeth unless otherwise noted) of similar age and
appearance were partially embedded in circular acrylic discs. The exposed
portion of each tooth was ground flat and parallel to the acrylic disc
using Grade 120 silicon carbide paper-backed abrasive mounted on a
lapidary wheel, in order to expose the dentin or enamel. During this and
subsequent grinding and polishing steps, the teeth were continuously
rinsed with water. Further grinding and polishing of the teeth was carried
out by mounting Grade 320 silicon carbide paper-backed abrasive and then
Grade 600 silicon carbide paper-backed abrasive on the lapidary wheel. The
polished teeth were stored in distilled water, and used for testing within
2 hours after polishing. The polished teeth were removed from the water
and dried using a stream of compressed air.
Samples were prepared using the indicated techniques to bond previously
prepared 5 mm diameter, 2 mm thick buttons of the indicated material. In
the case of metal, porcelain and precured composite buttons, the sample is
polished using a Grade 600 silicon carbide paper-backed abrasive mounted
on a lapidary wheel, in order to obtain a shiny surface. The polished and
dried metal or amalgam surface was sandblasted with aluminum oxide that
has an average particle size of 50 microns until the metal or set amalgam
surface had a uniform aluminum oxide surface. Porcelain is then silane
treated using 3M.TM. Scotchbond.TM. Ceramic Primer. Luting cement from the
3M.TM. Indirect Porcelain System is then applied to all buttons before
seating on the intended substrate. Excess luting cement is scraped away
after application of pressure to seat the button.
In the case of bonding uncured composite, previously prepared molds made
from approximately 2-mm thick "Teflon" sheet with a 5 mm diameter hole
were clamped to each prepared tooth so that the central axis of the hole
in the mold was normal to the tooth surface. The hole in each mold was
filled with dental composite material. It is believed that the choice of
restorative might affect the bond strength values obtained for a given
adhesive system. For example, some adhesive systems of the present
invention provide very strong bonds to hard tissue that are believed to
fail at the restorative-adhesive interface or within the restorative and
not at the adhesive-hard tissue interface. A higher strength restorative
may increase the measured bond strength for these adhesive systems.
Therefore, comparisons between different adhesive systems should be made,
wherever possible, using similar restorative systems. The teeth and molds
were allowed to stand for about 5 minutes at room temperature, then stored
in distilled water at 37.degree. C. for 24 hours unless otherwise noted.
The molds were then carefully removed from the teeth, leaving a molded
button of restorative attached to each tooth.
Adhesive strength was evaluated by mounting the acrylic disk in a holder
clamped in the jaws of an "Instron" apparatus with the polished tooth
surface oriented parallel to the direction of pull. A loop of wire (about
0.5 mm diameter) was placed around the restorative button adjacent to the
polished tooth surface. The ends of the orthodontic wire were clamped in
the pulling jaw of the Instron apparatus, thereby placing the bond in
shear stress. The bond was stressed until it (or the dentin or button)
failed, using a crosshead speed of 2 mm/min.
Shear adhesion to materials other than teeth was evaluated as follows:
First, the substrate to be tested (e.g.., metals, porcelain, set amalgam;
ten samples unless otherwise noted) were partially embedded in circular
acrylic discs. The exposed portion of each sample was polished flat and
parallel to the acrylic disc using Grade 600 silicon carbide paper-backed
abrasive mounted on a lapidary wheel, in order to obtain a shiny metal or
amalgam surface. During these polishing steps, the surface was
continuously rinsed with water. The polished metal or amalgam was removed
from the water and dried using a stream of water and oil-free compressed
air. The polished and dried metal or amalgam surface was sandblasted with
aluminum oxide that has an average particle size of 50 microns until the
metal or set amalgam surface had a uniform aluminum oxide surface. For a 5
mm diameter cross-section, this takes about 15 seconds. The sandblasted
metal or amalgam was then sonicated in water for 5 minutes so loose
alumina was removed. The samples were then removed from the water and
dried using an oil and water-free stream of compressed air.
The restorative materials were bonded to the thus prepared surfaces in the
same manner as above.
The following examples are offered to aid in understanding of the present
invention and are not to be construed as limiting the scope thereof.
Unless otherwise indicated, all parts and percentages are by weight. The
Copolymer used in these examples, unless otherwise noted, is an
ethylenically unsaturated acidic copolymer prepared like the precipitated
dry polymer of EXAMPLE 11 of U.S. Pat. No. 5,130,347. The adhesive used in
all examples, except as otherwise noted, was a two part curable adhesive,
wherein one part contained 0.25% CPQ, 0.38% DHEPT, 0.50% EDMAB, 61,79%
BisGMA and 37.08% HEMA. The second part contained 2.1% BPO, 0.093% BHT,
61.13% BisGMA and 36.68% HEMA. Where commercially available products were
tested, manufacturer's instructions were followed.
Experimental
EXAMPLE 1
The effect of the selection of etchants in the present system was evaluated
for bonding of cured restorative (Z100 restorative, commercially available
from 3M) to dentin following the bond strength protocol as defined above.
Various etchants were used in combination with a standard treatment
composition, which was three percent sodium benzenesulfinate in ethanol,
and a standard primer, which was 13.3% Copolymer/39.8% HEMA/46.9% water.
Bond strengths are reported in Table I.
TABLE I
______________________________________
SHEAR
ADHESIVE BOND
ETCHANT STRENGTH (kg/cm.sup.2)
______________________________________
10% maleic acid with H.sub.2 O rinse
104 .+-. 30
10% maleic acid-no rinse
130 .+-. 37
35% phosphoric acid with H.sub.2 O rinse
124 .+-. 52
No etch 0
35% phosphoric acid-no rinse
32 .+-. 27
______________________________________
This example shows that the adhesion of cured restorative to dentin was
significantly higher for a methodology that included an acid etch step
that left no insoluble salts on the surface of the dentin.
EXAMPLE 2
The effect of the selection of components incorporated in the treatment
composition for adhesion of precured composite (Z100 restorative,
commercially available from 3M) to dentin was evaluated with the use of a
standard etchant, which was 35% phosphoric acid with water rinse, and a
standard primer which was 13.3% Copolymer/39.8% HEMA/46.9% water. The
results of these bond strength evaluations are set forth in Table II.
TABLE II
______________________________________
TREATMENT SHEAR ADHESIVE BOND
COMPOSITION STRENGTH (kg/cm.sup.2)
______________________________________
3% SBS.sup.1 /water
171 .+-. 28
6% SBS/89% EtOH/5% H.sub.2 O
95 .+-. 66
9% SBS/83% EtOH/8% H.sub.2 O
129 .+-. 76
3% SBS/EtOH 131 .+-. 61
3.5% sodium meta bisulfite/H.sub.2 O
255 .+-. 31
4.5% sodium thio sulfate/H.sub.2 O
62 .+-. 45
2.3% sodium sulfite/H.sub.2 O
139 .+-. 56
3.6% DHEPT.sup.2 /EtOH
46 .+-. 30
3.0% DMAPE.sup.3 /EtOH
20 .+-. 16
3% DMAPE/Acetone 118 .+-. 39
3.6% DHEPT/Acetone
18 .+-. 15
1% SBS/EtOH 148 .+-. 50
6% DMAPE/EtOH 46 .+-. 64
10% DMAPE/EtOH 60 .+-. 35
ethanol (no electron donor).sup.4
73 .+-. 62
3% SBS/ethanol.sup.4
161 .+-. 26
______________________________________
.sup.1 sodium benzenesulfinate
.sup.2 N,Nbis-(2-hydroxyethyl)-p-toluidine
.sup.3 4(dimethylamino)-phenethyl alcohol
.sup.4 Testing performed on the same day for sideby-side comparison.
This example shows that good bond strengths are achieved using an electron
donor in the treatment solution when bonding precured composite buttons to
dentin.
EXAMPLE 3
The effect of selection of primers for adhesion of precured composite (Z100
restorative, commercially available from 3M) to dentin was evaluated by
the use of various primers with a standard acid etchant, which was a 35%
phosphoric acid followed by water rinse, together with a standard
treatment composition, which was 3% sodium benzenesulfinate in ethanol.
The results of these bond strength evaluations are reported in Table III.
TABLE III
______________________________________
SHEAR ADHE-
SIVE BOND
STRENGTH
PRIMER (kg/cm.sup.2)
______________________________________
13.3% Copolymer/39.8% HEMA/46.9% H.sub.2 O
111 .+-. 51
7% MDP.sup.1 /42.7% HEMA/50.3% H.sub.2 O
152 .+-. 37
2.4% phenol/44.9% HEMA/52.9% H.sub.2 O
86 .+-. 65
0.45% H.sub.2 O/44.8% HEMA/54.75% H.sub.2 O
93 .+-. 62
1.5% acetic acid/45.2% HEMA/53.3% H.sub.2 O
86 .+-. 66
2.9% maleic acid/44.6% HEMA/52.5% H.sub.2 O
118 .+-. 45
2.3% oxalic acid/44.9% HEMA/52.9% H.sub.2 O
80 .+-. 48
1.3% nitric acid/45.3% HEMA/53.4% H.sub.2 O
129 .+-. 54
0.92% HCl/41.7% HEMA/49.1% H.sub.2 O
84 .+-. 49
2.5% sulfuric acid/44.8% HEMA/52.8% H.sub.2 O
40 .+-. 30
1% Copolymer/41.3% H.sub.2 O/48.7% HEMA
128 .+-. 38
13% Copolymer/H.sub.2 O 53 .+-. 30
13% Copolymer/EtOH 24 .+-. 15
13% Copolymer/43.5% H.sub.2 O/43.5% EtOH
78 .+-. 36
7% MDP/13% Copolymer/79.6% H.sub.2 O
62 .+-. 48
50% Copolymer/23.0% HEMA/27.1% H.sub.2 O
4 .+-. 5
13% Copolymer/39.8% HEMA/46.9% EtOH
54 .+-. 27
No Primer 37 .+-. 24
______________________________________
.sup.1 methacryloxydecyl phosphate
This example shows that significant adhesion of a precured composite button
to dentin is possible using a primer as described for the present method.
EXAMPLE 4
The shear bond strength of the indicated adherends to dentin was evaluated
using an experimental system of the present invention (etchant-35%
phosphoric acid with water rinse, treatment composition-3% sodium
benzenesulfinate/ethanol, primer-13.3% Copolymer/39.8% HEMA/46.9% water).
The adhesive contained 2.1% BPO, 0.093% BHT, 61.13% BisGMA and 36.68%
HEMA. This system was compared to a commercially available dental adhesive
system following the bond strength protocol as defined above.
The non-precious metal contained 1.8% Beryllium, 4-6% molybdenum, 74-78%
Nickel and 12-15% Chromium. The semi-precious metal contained 80%
Palladium, 1.5% Silver and 2-5% Gold. The precious metal contained 62%
Gold, 9% Copper, 25% Silver and 3% Palladium. The precured composite was
Z100 (commercially available from 3M). The porcelain was Unitek Crystar
Body porcelain.
TABLE IV
______________________________________
SHEAR BOND TO DENTIN
Shear Adhesive Bond Strength (kg/cm.sup.2)
Adherend Exptl System All-Bond 2
______________________________________
Non-Precious metal
149 .+-. 56 148 .+-. 46
Semi-Precious metal
143 .+-. 20 187 .+-. 26
Precious metal
218 .+-. 36 231 .+-. 54
Precured Composite
131 .+-. 81 124 .+-. 23
Porcelain 60 .+-. 21 57 .+-. 39
______________________________________
This example shows that the experimental system of the present invention
achieves shear adhesive bond strengths of adherends to dentin that were at
least equal to the bond strengths of commercial products. The present
invention has advantage of being an easy to use self-curable adhesive
system. The All-Bond 2 product requires multiple applications of a primer
that must be mixed in the dental office.
EXAMPLE 5
The shear bond strength of the indicated adherends to enamel was evaluated
using an experimental system of the present invention (etchant-35%
phosphoric acid with rinse, treatment composition 3% sodium
benzenesulfinate/ethanol, primer-13.3% Copolymer/39.8% HEMA/46.9% water).
The adhesive contained 2.1% BPO, 0.093% BHT, 61.13% BisGMA and 36.68%
HEMA. This system was compared to a commercially available dental adhesive
system following the bond strength protocol as defined above. The
adherends were as described in Example 4.
TABLE V
______________________________________
SHEAR BOND TO ENAMEL
Shear Adhesive Bond Strength (kg/cm.sup.2)
Adherend Exptl System All-Bond 2
______________________________________
Non-Precious metal
263 .+-. 70 273 .+-. 54
Semi-Precious metal
144 .+-. 23 228 .+-. 63
Precious metal
218 .+-. 36 231 .+-. 54
Precured Composite
265 .+-. 77 228 .+-. 39
Porcelain 181 .+-. 67 153 .+-. 52
______________________________________
This example shows that the experimental system of the present invention
achieves shear adhesive bond strengths of adherends to enamel that were at
least equal to the bond strengths of commercial products. The present
invention has advantage of being an easy to use self-curable adhesive
system. The All-Bond 2 product requires multiple applications of a primer
that must be mixed in the dental office.
EXAMPLE 6
The shear bond strength of the indicated adherends to porcelain was
evaluated using an experimental system of the present invention
(etchant-35% phosphoric acid with rinse, treatment composition 3% sodium
benzenesulfinate/ethanol, primer-13.3% Copolymer/39.8% HEMA/46.9% water).
The adhesive contained 2.1% BPO, 0.093% BHT, 61.13% BisGMA and 36.68%
HEMA. The adherends were as described in Example 4.
TABLE VI
______________________________________
SHEAR BOND TO PORCELAIN
Shear Adhesive Bond Strength
Adherend (kg/cm.sup.2)
______________________________________
Porcelain 162 .+-. 32
Non-Precious metal
191 .+-. 32
Semi-Precious metal
193 .+-. 12
Precious metal
161 .+-. 21
______________________________________
This example shows that high shear bond strengths may be achieved using the
present method when adhering various adherends to porcelain.
EXAMPLE 7
The shear bond strength of the indicated adherends to previously cured
composite (Z100 restorative, commercially available fron 3M) was evaluated
using an experimental system of the present invention (etchant-35%
phosphoric acid with rinse, treatment composition 3% sodium
benzenesulfinate/ethanol, primer-13.3% Copolymer/39.8% HEMA/46.9% water).
The adhesive contained 2.1% BPO, 0.093% BHT, 61.13% BisGMA and 36.68%
HEMA. The adherends were as described in Example 4.
TABLE VII
______________________________________
SHEAR BOND TO COMPOSITE
Shear Adhesive Bond Strength
Adherend (kg/cm.sup.2)
______________________________________
Precured Composite
158 .+-. 30
Porcelain 202 .+-. 41
Non-Precious metal
266 .+-. 45
Semi-Precious metal
264 .+-. 42
Precious metal
232 .+-. 55
______________________________________
This example shows that high shear bond strengths may be achieved using the
present method when adhering various adherends to composites.
EXAMPLE 8
The shear bond strength of the indicated adherends to non-precious metal
was evaluated using an experimental system of the present invention
(etchant-35% phosphoric acid with rinse, treatment composition 3% sodium
benzenesulfinate/ethanol, primer-13.3% Copolymer/39.8% HEMA/46.9% water).
The adhesive contained 2.1% BPO, 0.093% BHT, 61.13% BisGMA and 36.68%
HEMA. The adherends were as described in Example 4.
TABLE VIII
______________________________________
SHEAR BOND TO NON-PRECIOUS METAL
Shear Adhesive Bond Strength
Adherend (kg/cm.sup.2)
______________________________________
Precured Composite
162 .+-. 30
Porcelain 200 .+-. 69
Non-Precious metal
308 .+-. 61
Semi-Precious metal
301 .+-. 40
Precious metal
281 .+-. 28
______________________________________
This example shows that high shear bond strengths may be achieved using the
present method when adhering various adherends to non-precious metal.
EXAMPLE 9
The shear bond strength of the indicated adherends to semi-precious metal
was evaluated using an experimental system of the present invention
(etchant-35% phosphoric acid with rinse, treatment composition 3% sodium
benzenesulfinate/ethanol, primer-13.3% Copolymer/39.8% HEMA/46.9% water).
The adhesive contained 2.1% BPO, 0.093% BHT, 61.13% BisGMA and 36.68%
HEMA. The adherends were as described in Example 4.
TABLE IX
______________________________________
SHEAR BOND TO SEMI-PRECIOUS METAL
Shear Adhesive Bond Strength
Adherend (kg/cm.sup.2)
______________________________________
Precured Composite
121 .+-. 27
Porcelain 145 .+-. 51
Non-Precious metal
308 .+-. 61
Semi-Precious metal
301 .+-. 40
Precious metal
281 .+-. 28
______________________________________
This example shows that high shear bond strengths may be achieved using the
present method when adhering various adherends to semi-precious metal.
EXAMPLE 10
The shear bond strength of the indicated adherends to precious metal was
evaluated using an experimental system of the present invention
(etchant-35% phosphoric acid with rinse, treatment composition 3% sodium
benzenesulfinate/ethanol, primer-13.3% Copolymer/39.8% HEMA/46.9% water).
The adhesive contained 2.1% BPO, 0.093% BHT, 61.13% BisGMA and 36.68%
HEMA. The adherends were as described in Example 4.
TABLE X
______________________________________
SHEAR BOND TO PRECIOUS METAL
Shear Adhesive Bond Strength
Adherend (kg/cm.sup.2)
______________________________________
Precured Composite
126 .+-. 22
Porcelain 97 .+-. 19
Non-Precious metal
133 .+-. 17
Semi-Precious metal
147 .+-. 19
Precious metal
126 .+-. 30
______________________________________
This example shows that high shear bond strengths may be achieved using the
present method when adhering various adherends to precious metal.
EXAMPLE 11
The shear bond strength of the indicated adherends to set amalgam was
evaluated using an experimental system of the present invention
(etchant-35% phosphoric acid with rinse, treatment composition 3% sodium
benzenesulfinate/ethanol, primer-13.3% Copolymer/39.8% HEMA/46.9% water).
The adhesive contained 2.1% BPO, 0.093% BHT, 61.13% BisGMA and 36.68%
HEMA. The adherends were as described in Example 4. The set amalgam was
Disperalloy.TM. amalgam.
TABLE XI
______________________________________
SHEAR BOND TO SET AMALGAM
Shear Adhesive Bond Strength
Adherend (kg/cm.sup.2)
______________________________________
Precured Composite
123 .+-. 38
Porcelain 113 .+-. 40
Non-Precious metal
195 .+-. 54
Semi-Precious metal
172 .+-. 53
Precious metal
136 .+-. 48
______________________________________
This example shows that high shear bond strengths may be achieved using the
present method when adhering various adherends to set amalgam.
EXAMPLE 12
The shear bond strength of the indicated adherends to glass ionomer core
was evaluated using an experimental system of the present invention
(etchant-35% phosphoric acid with rinse, treatment composition 3% sodium
benzenesulfinate/ethanol, primer-13.3% Copolymer/39.8% HEMA/46.9% water).
The adhesive contained 2.1% BPO, 0,093% BHT, 61.13% BisGMA and 36.68%
HEMA. The adherends were as described in Example 4. The glass ionomer core
was 3M.TM. Vitremer.TM. glass ionomer restorative/core buildup material.
TABLE XII
______________________________________
SHEAR BOND TO GLASS IONOMER CORE
Shear Adhesive Bond Strength
Adherend (kg/cm.sup.2)
______________________________________
Precured Composite
106 .+-. 34
Porcelain 185 .+-. 52
Non-Precious metal
193 .+-. 40
Semi-Precious metal
187 .+-. 31
Precious metal
196 .+-. 39
______________________________________
This example shows that high shear bond strengths may be achieved using the
present method when adhering various adherends to glass ionomer core.
EXAMPLE 13
The shear bond strength of a self-cure composite material (3M.TM. P-10.TM.
Resin Bonded Ceramic restorative from 3M) to various dental surfaces was
evaluated using an experimental system of the present invention
(etchant-35% phosphoric acid with rinse, treatment composition 3% sodium
benzenesulfinate/ethanol, primer-13.3% Copolymer/39.8% HEMA/46.9% water).
This system was compared to a commercially available dental adhesive
system following the bond strength protocol as defined above. The
adherends were as described in Example 4.
TABLE XIII
______________________________________
SHEAR BOND OF COMPOSITE TO
VARIOUS DENTAL SURFACES
Exptl
Dental Surface System All-Bond 2
______________________________________
Dentin 179 .+-. 39
136 .+-. 38
Enamel 278 .+-. 69
253 .+-. 52
Porcelain 135 .+-. 34
154 .+-. 15
Composite 191 .+-. 27
187 .+-. 76
Non-Precious Metal
139 .+-. 29
183 .+-. 83
Semi-Precious Metal
108 .+-. 40
181 .+-. 59
Precious Metal 123 .+-. 49
90 .+-. 42
Set Amalgam 131 .+-. 30
153 .+-. 34
______________________________________
This example shows that high shear bond strengths may be achieved using the
present method when adhering composite material to various dental
surfaces. The set amalgam was Disperalloy.TM. amalgam.
EXAMPLE 14
To show the use of alternative adhesive components, adhesion of a precured
composite button was carried out as in Example 4 with the following
adhesive components:
Part A-0.25% CPQ, 0.38% DHEPT, 0.50% EDMAB, 61,79% BisGMA and 37.08% HEMA.
Part B-2.1% BPO, 0.093% BHT, 61.13% BisGMA and 36.68% HEMA.
TABLE XIV
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SHEARBOND STRENGTH
ADHESIVE SYSTEM kg/cm.sup.2
______________________________________
Part A & B 155 .+-. 52
Part B only 147 .+-. 76
Part A only 122 .+-. 16
______________________________________
This example shows that high shear bond strengths may be achieved using the
present method when adhering composite material to dentin using various
combinations of adhesive components.
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